ASAHI KASEI
[AK4182A]
Serial Interface
The AK4182A is controlled via 4-wire serial interface, CSN, DCLK, DIN, DOUT.
Please see “ Switching Characteristics” for the detail.
CSN
7
1
2
3
4
5
6
8
9
10
11
12
13
14 15 16 17 18 19 20 21
22
23
24
DCLK
SER/
DFR
SER/
DFR
S
A2
A1
A0
MO
PD1
PD0
S
A2
A1
A0
MO
PD1
PD0
DIN
Hi-Z
Hi-Z
BUSY
11
10
9
8
7
6
5
4
3
2
1
0
11 10
DOUT
Touch Screen Driver SW
(SER/ DFR = ”1”, PD0 = ”0” )
Touch Screen Driver
(SER/ DFR = ”0”, PD0 = ”0” )
Figure 7 Serial Interface
BUSY and DOUT goes to “L” from Hi-Z state at the falling edge of CSN. The AK4182A latches the 8bit control word serially via
DIN at the rising edge of DCLK. As the AK4182A starts the command decoding at the first “H” bit after CSN= “↓”, MSB (S bit)
of the command must be “H”.
Tracking time is the period from the falling edge of 5th DCLK to the falling edge of 8th DCLK. If SER/ DFR = “1”, PD0= “0”,
and if analog input is X-axis or Y-axis (the measurement is the pen position or pen pressure), the touch screen driver switches are
turned ON for this 3DCLK period. If SER/ DFR = “0”, the switches are turned ON for the period from 5DCLK↓ to 20 DCLK↓.
BUSY is “H” for one DCLK period, which is from 8DCLK↓ to 9DCLK↓. BUSY is “L” for other period.
The AK4182A outputs A/D data with MSB first via DOUT from the falling edge of 9th DCLK.
DIN must keep low state for minimum 7 DCLK times (9th-15th DCLK) after command is sent on the DIN.
The AK4182A can output one A/D data per 15 DCLK clock cycles for the fastest way as shown in the dotted line of the Figure 7.
MS0482-E-00
13
2006/03
AKM [ ASAHI KASEI MICROSYSTEMS ]
